func NewModel(cfg *config.Wrapper, db *bolt.DB) *Model {
	m := &Model{
		cfg: cfg,
		db:  db,

		protoConn: make(map[protocol.DeviceID]stmodel.Connection),
		pmut:      sync.NewRWMutex(),

		blockCaches:   make(map[string]*fileblockcache.FileBlockCache),
		treeCaches:    make(map[string]*filetreecache.FileTreeCache),
		devicesByFile: make(map[string]map[string][]protocol.DeviceID),
		filesByDevice: make(map[string]map[protocol.DeviceID][]string),
		fmut:          sync.NewRWMutex(),
	}

	for _, folderCfg := range m.cfg.Folders() {
		folder := folderCfg.ID

		fbc, err := fileblockcache.NewFileBlockCache(m.cfg, db, folderCfg)
		if err != nil {
			l.Warnln("Skipping folder", folder, "because fileblockcache init failed:", err)
		}
		m.blockCaches[folder] = fbc
		m.treeCaches[folder] = filetreecache.NewFileTreeCache(m.cfg, db, folder)

		m.devicesByFile[folder] = make(map[string][]protocol.DeviceID)
		m.filesByDevice[folder] = make(map[protocol.DeviceID][]string)
	}

	return m
}

func NewDiscoverer(id protocol.DeviceID, addresses []string) *Discoverer {
	return &Discoverer{
		myID:           id,
		listenAddrs:    addresses,
		localBcastIntv: 30 * time.Second,
		cacheLifetime:  5 * time.Minute,
		negCacheCutoff: 3 * time.Minute,
		registry:       make(map[protocol.DeviceID][]CacheEntry),
		lastLookup:     make(map[protocol.DeviceID]time.Time),
		registryLock:   sync.NewRWMutex(),
		mut:            sync.NewRWMutex(),
	}
}

func NewModel(cfg *config.Wrapper, db *bolt.DB) *Model {
	var lmutex sync.Mutex
	m := &Model{
		cfg:         cfg,
		db:          db,
		pinnedFiles: make(map[string][]string),

		blockCaches:   make(map[string]*fileblockcache.FileBlockCache),
		treeCaches:    make(map[string]*filetreecache.FileTreeCache),
		folderDevices: make(map[string][]protocol.DeviceID),
		pulls:         make(map[string]map[string]*blockPullStatus),
		fmut:          stsync.NewRWMutex(),

		lmut: sync.NewCond(&lmutex),

		protoConn: make(map[protocol.DeviceID]connections.Connection),
		pmut:      stsync.NewRWMutex(),
	}

	for _, folderCfg := range m.cfg.Folders() {
		folder := folderCfg.ID

		fbc, err := fileblockcache.NewFileBlockCache(m.cfg, db, folderCfg)
		if err != nil {
			l.Warnln("Skipping folder", folder, "because fileblockcache init failed:", err)
			continue
		}
		m.blockCaches[folder] = fbc
		m.treeCaches[folder] = filetreecache.NewFileTreeCache(folderCfg, db, folder)

		m.folderDevices[folder] = make([]protocol.DeviceID, len(folderCfg.Devices))
		for i, device := range folderCfg.Devices {
			m.folderDevices[folder][i] = device.DeviceID
		}

		m.pulls[folder] = make(map[string]*blockPullStatus)

		m.pinnedFiles[folder] = make([]string, len(folderCfg.PinnedFiles))
		copy(m.pinnedFiles[folder], folderCfg.PinnedFiles)
		sort.Strings(m.pinnedFiles[folder])
		m.unpinUnnecessaryBlocks(folder)
	}

	m.removeUnconfiguredFolders()

	for i := 0; i < 4; i++ {
		go m.backgroundPinnerRoutine()
	}

	return m
}

func TestSourceFileOK(t *testing.T) {
	s := sharedPullerState{
		realName: "testdata/foo",
		mut:      sync.NewRWMutex(),
	}

	fd, err := s.sourceFile()
	if err != nil {
		t.Fatal(err)
	}
	if fd == nil {
		t.Fatal("Unexpected nil fd")
	}

	bs := make([]byte, 6)
	n, err := fd.Read(bs)
	if err != nil {
		t.Fatal(err)
	}

	if n != len(bs) {
		t.Fatalf("Wrong read length %d != %d", n, len(bs))
	}
	if string(bs) != "foobar" {
		t.Fatalf("Wrong contents %s != foobar", string(bs))
	}

	if err := s.failed(); err != nil {
		t.Fatal(err)
	}
}

func newStaticsServer(theme, assetDir string) *staticsServer {
	s := &staticsServer{
		assetDir: assetDir,
		assets:   auto.Assets(),
		mut:      sync.NewRWMutex(),
		theme:    theme,
	}

	seen := make(map[string]struct{})
	// Load themes from compiled in assets.
	for file := range auto.Assets() {
		theme := strings.Split(file, "/")[0]
		if _, ok := seen[theme]; !ok {
			seen[theme] = struct{}{}
			s.availableThemes = append(s.availableThemes, theme)
		}
	}
	if assetDir != "" {
		// Load any extra themes from the asset override dir.
		for _, dir := range dirNames(assetDir) {
			if _, ok := seen[dir]; !ok {
				seen[dir] = struct{}{}
				s.availableThemes = append(s.availableThemes, dir)
			}
		}
	}

	return s
}

func newStaticClient(uri *url.URL, certs []tls.Certificate, invitations chan protocol.SessionInvitation, timeout time.Duration) RelayClient {
	closeInvitationsOnFinish := false
	if invitations == nil {
		closeInvitationsOnFinish = true
		invitations = make(chan protocol.SessionInvitation)
	}

	return &staticClient{
		uri:         uri,
		invitations: invitations,

		closeInvitationsOnFinish: closeInvitationsOnFinish,

		config: configForCerts(certs),

		messageTimeout: time.Minute * 2,
		connectTimeout: timeout,

		stop:    make(chan struct{}),
		stopped: make(chan struct{}),

		mut:       sync.NewRWMutex(),
		connected: false,
	}
}

func NewService(cfg *config.Wrapper, myID protocol.DeviceID, mdl Model, tlsCfg *tls.Config, discoverer discover.Finder,
	bepProtocolName string, tlsDefaultCommonName string, lans []*net.IPNet) *Service {

	service := &Service{
		Supervisor: suture.New("connections.Service", suture.Spec{
			Log: func(line string) {
				l.Infoln(line)
			},
		}),
		cfg:                  cfg,
		myID:                 myID,
		model:                mdl,
		tlsCfg:               tlsCfg,
		discoverer:           discoverer,
		conns:                make(chan internalConn),
		bepProtocolName:      bepProtocolName,
		tlsDefaultCommonName: tlsDefaultCommonName,
		lans:                 lans,
		limiter:              newLimiter(cfg),
		natService:           nat.NewService(myID, cfg),

		listenersMut:   sync.NewRWMutex(),
		listeners:      make(map[string]genericListener),
		listenerTokens: make(map[string]suture.ServiceToken),

		// A listener can fail twice, rapidly. Any more than that and it
		// will be put on suspension for ten minutes. Restarts and changes
		// due to config are done by removing and adding services, so are
		// not subject to these limitations.
		listenerSupervisor: suture.New("c.S.listenerSupervisor", suture.Spec{
			Log: func(line string) {
				l.Infoln(line)
			},
			FailureThreshold: 2,
			FailureBackoff:   600 * time.Second,
		}),

		curConMut:         sync.NewMutex(),
		currentConnection: make(map[protocol.DeviceID]completeConn),
	}
	cfg.Subscribe(service)

	// There are several moving parts here; one routine per listening address
	// (handled in configuration changing) to handle incoming connections,
	// one routine to periodically attempt outgoing connections, one routine to
	// the the common handling regardless of whether the connection was
	// incoming or outgoing.

	service.Add(serviceFunc(service.connect))
	service.Add(serviceFunc(service.handle))
	service.Add(service.listenerSupervisor)

	raw := cfg.RawCopy()
	// Actually starts the listeners and NAT service
	service.CommitConfiguration(raw, raw)

	return service
}

func NewService(id protocol.DeviceID, cfg *config.Wrapper) *Service {
	return &Service{
		id:  id,
		cfg: cfg,

		timer: time.NewTimer(0),
		mut:   sync.NewRWMutex(),
	}
}

func NewService(id protocol.DeviceID, cfg *config.Wrapper) *Service {
	return &Service{
		id:  id,
		cfg: cfg,

		immediate: make(chan chan struct{}),
		timer:     time.NewTimer(time.Second),

		mut: sync.NewRWMutex(),
	}
}

func TestProgressEmitter(t *testing.T) {
	w := events.Default.Subscribe(events.DownloadProgress)

	c := config.Wrap("/tmp/test", config.Configuration{})
	c.SetOptions(config.OptionsConfiguration{
		ProgressUpdateIntervalS: 0,
	})

	p := NewProgressEmitter(c)
	go p.Serve()
	p.interval = 0

	expectTimeout(w, t)

	s := sharedPullerState{
		updated: time.Now(),
		mut:     sync.NewRWMutex(),
	}
	p.Register(&s)

	expectEvent(w, t, 1)
	expectTimeout(w, t)

	s.copyDone(protocol.BlockInfo{})

	expectEvent(w, t, 1)
	expectTimeout(w, t)

	s.copiedFromOrigin()

	expectEvent(w, t, 1)
	expectTimeout(w, t)

	s.pullStarted()

	expectEvent(w, t, 1)
	expectTimeout(w, t)

	s.pullDone(protocol.BlockInfo{})

	expectEvent(w, t, 1)
	expectTimeout(w, t)

	p.Deregister(&s)

	expectEvent(w, t, 0)
	expectTimeout(w, t)

}

func NewBlockFinder(db *leveldb.DB, cfg *config.Wrapper) *BlockFinder {
	if blockFinder != nil {
		return blockFinder
	}

	f := &BlockFinder{
		db:  db,
		mut: sync.NewRWMutex(),
	}

	f.CommitConfiguration(config.Configuration{}, cfg.Raw())
	cfg.Subscribe(f)

	return f
}

func newDynamicClient(uri *url.URL, certs []tls.Certificate, invitations chan protocol.SessionInvitation) RelayClient {
	closeInvitationsOnFinish := false
	if invitations == nil {
		closeInvitationsOnFinish = true
		invitations = make(chan protocol.SessionInvitation)
	}
	return &dynamicClient{
		pooladdr:                 uri,
		certs:                    certs,
		invitations:              invitations,
		closeInvitationsOnFinish: closeInvitationsOnFinish,

		mut: sync.NewRWMutex(),
	}
}

func init() {
	for _, proto := range []string{"udp", "udp4", "udp6"} {
		Register(proto, func(uri *url.URL, pkt *Announce) (Client, error) {
			c := &UDPClient{
				wg:  sync.NewWaitGroup(),
				mut: sync.NewRWMutex(),
			}
			err := c.Start(uri, pkt)
			if err != nil {
				return nil, err
			}
			return c, nil
		})
	}
}

func TestAssetsDir(t *testing.T) {
	// For any given request to $FILE, we should return the first found of
	//  - assetsdir/$THEME/$FILE
	//  - compiled in asset $THEME/$FILE
	//  - assetsdir/default/$FILE
	//  - compiled in asset default/$FILE

	// The asset map contains compressed assets, so create a couple of gzip compressed assets here.
	buf := new(bytes.Buffer)
	gw := gzip.NewWriter(buf)
	gw.Write([]byte("default"))
	gw.Close()
	def := buf.Bytes()

	buf = new(bytes.Buffer)
	gw = gzip.NewWriter(buf)
	gw.Write([]byte("foo"))
	gw.Close()
	foo := buf.Bytes()

	e := &staticsServer{
		theme:    "foo",
		mut:      sync.NewRWMutex(),
		assetDir: "testdata",
		assets: map[string][]byte{
			"foo/a":     foo, // overridden in foo/a
			"foo/b":     foo,
			"default/a": def, // overridden in default/a (but foo/a takes precedence)
			"default/b": def, // overridden in default/b (but foo/b takes precedence)
			"default/c": def,
		},
	}

	s := httptest.NewServer(e)
	defer s.Close()

	// assetsdir/foo/a exists, overrides compiled in
	expectURLToContain(t, s.URL+"/a", "overridden-foo")

	// foo/b is compiled in, default/b is overridden, return compiled in
	expectURLToContain(t, s.URL+"/b", "foo")

	// only exists as compiled in default/c so use that
	expectURLToContain(t, s.URL+"/c", "default")

	// only exists as overridden default/d so use that
	expectURLToContain(t, s.URL+"/d", "overridden-default")
}

func TestSourceFileBad(t *testing.T) {
	s := sharedPullerState{
		realName: "nonexistent",
		mut:      sync.NewRWMutex(),
	}

	fd, err := s.sourceFile()
	if err == nil {
		t.Fatal("Unexpected nil error")
	}
	if fd != nil {
		t.Fatal("Unexpected non-nil fd")
	}
	if err := s.failed(); err == nil {
		t.Fatal("Unexpected nil failed()")
	}
}

// Update updates internal state of what has been downloaded into the temporary
// files by the remote device for this specific folder.
func (t *deviceDownloadState) Update(folder string, updates []protocol.FileDownloadProgressUpdate) {
	t.mut.RLock()
	f, ok := t.folders[folder]
	t.mut.RUnlock()

	if !ok {
		f = &deviceFolderDownloadState{
			mut:   sync.NewRWMutex(),
			files: make(map[string]deviceFolderFileDownloadState),
		}
		t.mut.Lock()
		t.folders[folder] = f
		t.mut.Unlock()
	}

	f.Update(updates)
}

func (s *Service) NewMapping(protocol Protocol, ip net.IP, port int) *Mapping {
	mapping := &Mapping{
		protocol: protocol,
		address: Address{
			IP:   ip,
			Port: port,
		},
		extAddresses: make(map[string]Address),
		mut:          sync.NewRWMutex(),
	}

	s.mut.Lock()
	s.mappings = append(s.mappings, mapping)
	s.mut.Unlock()

	return mapping
}

func NewSvc(cfg *config.Wrapper, tlsCfg *tls.Config) *Svc {
	conns := make(chan *tls.Conn)

	svc := &Svc{
		Supervisor: suture.New("Svc", suture.Spec{
			Log: func(log string) {
				if debug {
					l.Debugln(log)
				}
			},
			FailureBackoff:   5 * time.Minute,
			FailureDecay:     float64((10 * time.Minute) / time.Second),
			FailureThreshold: 5,
		}),
		cfg:    cfg,
		tlsCfg: tlsCfg,

		tokens:      make(map[string]suture.ServiceToken),
		clients:     make(map[string]*client.ProtocolClient),
		mut:         sync.NewRWMutex(),
		invitations: make(chan protocol.SessionInvitation),
		conns:       conns,
	}

	rcfg := cfg.Raw()
	svc.CommitConfiguration(rcfg, rcfg)
	cfg.Subscribe(svc)

	receiver := &invitationReceiver{
		tlsCfg:      tlsCfg,
		conns:       conns,
		invitations: svc.invitations,
		stop:        make(chan struct{}),
	}

	eventBc := &eventBroadcaster{
		svc: svc,
	}

	svc.Add(receiver)
	svc.Add(eventBc)

	return svc
}

func (s *Service) NewMapping(protocol Protocol, ip net.IP, port int) *Mapping {
	mapping := &Mapping{
		protocol: protocol,
		address: Address{
			IP:   ip,
			Port: port,
		},
		extAddresses: make(map[string]Address),
		mut:          sync.NewRWMutex(),
	}

	s.mut.Lock()
	s.mappings = append(s.mappings, mapping)
	// Reset the timer while holding the lock, see process() for explanation
	s.timer.Reset(time.Second)
	s.mut.Unlock()

	return mapping
}

// Test creating temporary file inside read-only directory
func TestReadOnlyDir(t *testing.T) {
	// Create a read only directory, clean it up afterwards.
	os.Mkdir("testdata/read_only_dir", 0555)
	defer func() {
		os.Chmod("testdata/read_only_dir", 0755)
		os.RemoveAll("testdata/read_only_dir")
	}()

	s := sharedPullerState{
		tempName: "testdata/read_only_dir/.temp_name",
		mut:      sync.NewRWMutex(),
	}

	fd, err := s.tempFile()
	if err != nil {
		t.Fatal(err)
	}
	if fd == nil {
		t.Fatal("Unexpected nil fd")
	}

	s.fail("Test done", nil)
	s.finalClose()
}